In general, fine patterns used in a semiconductor circuit device and display device such as an LCD, a PDP, and the like are formed by a photolithography using a photoresist and generally, manufactured through coating, exposing, developing, cleaning, and curing processes.
However, the photolithography has an advantage capable of precisely acquiring a desired pattern, but has disadvantages of performing a process having lots of steps, using various kinds of materials in order to maximize an effect of the photoresist, and consuming a lot of photoresist in a coating process and the like.
Recently, in order to solve the disadvantages of the photoresist, a technique of acquiring fine patterns by a roll printing method has been proposed to be researched and developed.
The roll printing apparatus for forming a pattern may be variously applied to methods such as offset printing, reverse offset printing, roll-to-roll printing, and the like and may be widely applied to colors of red R, green G, and blue B which are constituent elements of a color filter and black matrix (BM) patterns, patterns for electrode formation of a thin film transistor (TFT) and a plasma display panel (PDP), pattern transfer of a barrier material.
The roll printing apparatus generally comprises a coater, a printing roll, a printing roll driving device, a cliché, or a driving device for a substrate stage and stage alignment as the most basic constituent element. In addition, the roll printing apparatus may further comprise a cliché and/or pipe cleaning device, a drying device for drying a blanket by absorbing a solvent absorbed in the blanket, various sensor devices, and the like.
Precision of the pattern formed by the roll printing method and pattern transfer efficiency largely depends on process conditions such as a coating state of a roll or a blanket of the roll from the coater, a volatile degree and a waiting time of a solvent before being transferred to the cliché or substrate after coating, a printing pressure formed by a gap between a stage and a roll or blanket during transfer, and the like.
Particularly, during the coating with the roll or the blanket which is the first step of the roll printing process, uniformity of the entire patterns and whether or not to form various forms of spots are determined according to the coating state.
In the roll printing apparatus, generally, after the printing roll performs a printing process once, until the printing roll is prepared again and the printing process such as the coating on the printing roll and the like is performed, there is a disadvantage in that a tack time is inevitably required.
Herein, the tack time, as a time taken when the next glass substrate is carried in again after one product is carried out, is adjusted by controlling the number of other equipment based on a time taken when the glass substrate is carried in to and carried out from photo equipment in manufacturing of a liquid crystal display (LCD) and even in the printing roll, similarly, means a time taken when one printing roll is in and out. In the case of the roll printing, a limitation occurs in that a production speed is relatively slower than the photo equipment due to the tack time.